recon wrote: It seems to me that close shaves with asteroids are getting more common. I hear about one every two months or so.

The Minor Planet Center (MPC) has a regularly (like every day, maybe even every hour) updated page on NEOs - Near Earth Objects.

"Close shaves" certainly *seem* to be getting more common! However, it's almost surely because a) the press is more readily picking the stories up, and b) we're getting much, much better at finding them.